Low-Complexity MISO Cache-Aided Communication via Meta-User Scheduling

Abstract:
We present a novel low-complexity scheme for cache-aided communication, where a multi-antenna base station serves multiple single-antenna mobile users. The scheme is based on dividing the users into meta-users, where all users in the same meta-user store the same content during the placement phase. The inter meta-user interference is mitigated by using the cache as well as zero forcing, while the interference between users of the same meta-user is mitigated by zero forcing. Compared to the current state of the art, this scheme is feasible for a wider range of parameters. Moreover, while still achieving the optimal number of degrees of freedom (DoF), the proposed scheme imposes the same or less complexity compared to all the known schemes for each set of parameters. Consequently, the proposed scheme enables practical implementation of cache-aided communication for a large number of users.